Valsartan. Molecular model of the drug valsartan (C24.H29.N5.O3). This is an angiotensin receptor blocker sold under the brand name Diovan. It is used to treat high blood pressure, congestive heart failure, and to reduce death for people with left ventricular dysfunction after having had a heart attack. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogens (white), nitrogen (blue) and oxygen (red).